/*
 * Copyright (c) 2003-2009 Israfil Consulting Services Corporation
 * Copyright (c) 2003-2009 Christian Edward Gruber
 * All Rights Reserved
 * 
 * This software is licensed under the Berkeley Standard Distribution license,
 * (BSD license), as defined below:
 * 
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this 
 *    list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice, 
 *    this list of conditions and the following disclaimer in the documentation 
 *    and/or other materials provided with the distribution.
 * 3. Neither the name of Israfil Consulting Services nor the names of its contributors 
 *    may be used to endorse or promote products derived from this software without 
 *    specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND 
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
 * IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 
 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, 
 * OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
 * OF SUCH DAMAGE.
 * 
 * $Id: DynamicUtil.java 91 2006-08-03 21:38:24Z cgruber $
 */
package net.israfil.foundation.dynamic;

import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.logging.Level;
import java.util.logging.Logger;

import net.israfil.foundation.collections.ArrayUtils;

/**
 * Utilities used for the implementation of Dynamic and
 * related interfaces.
 * 
 * @author <a href="mailto:cgruber@israfil.net">Christian Edward Gruber </a>
 */
public final class DynamicUtil  {
	private static Logger logger = Logger.getLogger(DynamicUtil.class.getName());

	private DynamicUtil() {}
	
	static Map<String, Class<?>>   _primitiveTypes           = new HashMap<String, Class<?>>();
    static Map<Class<?>, Class<?>> _primitiveTypeEquivalents = new HashMap<Class<?>, Class<?>>();
    static Map<Class<?>, Class<?>> _boxedTypeEquivalents     = new HashMap<Class<?>, Class<?>>();
    static {
        _primitiveTypes.put("boolean",boolean.class);
        _primitiveTypeEquivalents.put(Boolean.class,boolean.class);
        _boxedTypeEquivalents.put(boolean.class,Boolean.class);
        _primitiveTypes.put("int",int.class);
        _primitiveTypeEquivalents.put(Integer.class,int.class);
        _boxedTypeEquivalents.put(int.class,Integer.class);
        _primitiveTypes.put("long",long.class);
        _primitiveTypeEquivalents.put(Long.class,long.class);
        _boxedTypeEquivalents.put(long.class,Long.class);
        _primitiveTypes.put("short",short.class);
        _primitiveTypeEquivalents.put(Short.class,short.class);
        _boxedTypeEquivalents.put(short.class,Short.class);
        _primitiveTypes.put("byte",byte.class);
        _primitiveTypeEquivalents.put(Byte.class,byte.class);
        _boxedTypeEquivalents.put(byte.class,Byte.class);
        _primitiveTypes.put("char",char.class);
        _primitiveTypeEquivalents.put(Character.class,char.class);
        _boxedTypeEquivalents.put(char.class,Character.class);
        _primitiveTypes.put("double",double.class);
        _primitiveTypeEquivalents.put(Double.class,double.class);
        _boxedTypeEquivalents.put(double.class,Double.class);
        _primitiveTypes.put("float",float.class);
        _primitiveTypeEquivalents.put(Float.class,float.class);
        _boxedTypeEquivalents.put(float.class,Float.class);
    }
    public static boolean hasPrimitiveTypeEquivalent(Class<?> c) {
        return _primitiveTypeEquivalents.containsKey(c);
    }

    public static Class<?> getPrimitiveTypeEquivalent(Class<?> c) {
        return _primitiveTypeEquivalents.get(c);
    }

    public static boolean hasBoxedTypeEquivalent(Class<?> c) {
        return _boxedTypeEquivalents.containsKey(c);
    }

    public static Class<?> getBoxedTypeEquivalent(Class<?> c) {
        return _boxedTypeEquivalents.get(c);
    }

    protected static final Map<Class<?>, Set<Class<?>>> classes = new HashMap<Class<?>, Set<Class<?>>>();

    public static Set<Class<?>> getAllParentTypes(Class<?> c) {
		if (!classes.containsKey(c)) {
			Set<Class<?>> parents = new HashSet<Class<?>>();
            for (Class<?> cType = c; cType != Object.class && cType != null; cType = cType
                    .getSuperclass()) {
				parents.add(cType);
				addSuperInterfaces(parents,cType);
			}
			parents.add(Object.class);
			parents.remove(c);
			classes.put(c,parents);
		}
		return classes.get(c);
	}
	
	public static void addSuperInterfaces(Set<Class<?>> set, Class<?> c) {
		if (c == null || c.getInterfaces() == null) return;
		for (Class<?> i : c.getInterfaces()) {
			set.add(i);
			addSuperInterfaces(set,i);
		}
	}
	
    /**
	 * Conveniently get a field from an object, automatically trapping
	 * exceptions and returning the Field or null if no such field exists.
	 */
	public static Field getField(Object receiver, String attributeName) {
		Field f = null;
		try {
			f = receiver.getClass().getField(attributeName);
		} catch (NoSuchFieldException e) {
			return null;
		}
		return f;
	}
	
	
	
    /**
     * @see org.israfil.maveric.Dynamic#respondsTo(java.lang.String)
     */
    public static boolean respondsTo(Object receiver, String selector) {
        return (getMethodForSelector(receiver,selector) != null);
    }
    
    public static Method getMethodForSelector(Object receiver, String selector) {
        if (receiver instanceof Class) 
            return getMethodForSelector((Class<?>) receiver, selector);
        return getMethodForSelector(receiver.getClass(),selector);
    }
    
    public static Method getMethodForSelector(Class<?> receiverClass,
            String selector) {
    	try {
    		return _getMethodForSelector(receiverClass,selector);
    	} catch (ClassNotFoundException e) { 
    		throw new RuntimeException(e); 
    	} catch (NoSuchMethodException e) { 
    		return null;
    	} 
    }
    
    protected static Method _getMethodForSelector(Class<?> receiverClass,
            String selector) throws ClassNotFoundException,
            NoSuchMethodException {
        StringTokenizer st = new StringTokenizer(selector,":");
        Class<?>[] paramTypes = new Class[st.countTokens() - 1];
        String methodName = st.nextToken();
        ClassLoader loader = Thread.currentThread().getContextClassLoader();
        for (int i = 0; st.hasMoreTokens(); i++) {
            String className = st.nextToken();
            if (DynamicUtil._primitiveTypes.containsKey(className)) 
                paramTypes[i] = (Class<?>) DynamicUtil._primitiveTypes
                        .get(className);
            else paramTypes[i] = loader.loadClass(className);
        }
        return receiverClass.getMethod(methodName,paramTypes);
    }

    /**
     * @see org.israfil.maveric.Dynamic#perform(java.lang.String, java.lang.Object[])
     */
    public static Object performOn(Object receiver, String selector, Object ... parameters) {
    	if (parameters == null) parameters = new Object[]{};
        Method m = getMethodForSelector(receiver,selector);
        try { 
        	if (m != null) return m.invoke(receiver,parameters); 
        	//else return null;
        	else throw new NoSuchMethodError("No public method defined with selector \""+selector+"\"");
        } catch (InvocationTargetException ite) {
            logger.log(Level.FINE,ite.getClass().getName()+" thrown attempting to invoke selector: " + selector + " on "+receiver,ite); 
            if (ite.getCause() != null) throw new RuntimeException(ite.getCause());
            else throw new RuntimeException(ite);
        } catch (IllegalAccessException iae) {
            logger.log(Level.FINE,iae.getClass().getName()+" thrown attempting to invoke selector: " + selector + " on "+receiver,iae); 		
            throw new RuntimeException(iae);
        } 
    }

    /**
     * Construct an object of the given named class with the provided 
     * constructor parameters.  If there is no such class or no 
     * constructor is found that is appropriate to these parameters,
     * the method will return null;
     * 
     * @param className The fully qualified name of a Class object to be instantiated.
     * @param parameters Optional parameters for the discovered constructor
     * @return an instance of the named class, or null if no such class or constructor is found.
     */
    public static Object construct(String className, Object ... parameters) {
    	try {
    		Class<?> clazz = Thread.currentThread().getContextClassLoader()
                    .loadClass(className);
    		return construct(clazz,parameters);
    	} catch (ClassNotFoundException e) {
            logger.log(Level.FINE,e.getClass().getName()+" thrown attempting to construct a " + className + ".", e); 		
    		return null;
    	}
    }
    /**
     * Construct an object of the given class with the provided 
     * constructor parameters.  If there is no such class or no 
     * constructor is found that is appropriate to these parameters,
     * the method will return null;
     * 
     * @param c A Class object to be instantiated.
     * @param parameters Optional parameters for the discovered constructor
     * @return an instance of the named class, or null if no such class or constructor is found.
     */
    public static <T> T construct(Class<T> c, Object ... parameters) {
    	Class<?> [] parmTypes = new Class<?>[parameters.length];
    	for (int i = 0; i < parmTypes.length; i++) {
    		parmTypes[i] = parameters[i].getClass();
    	}
    	return construct(c,parmTypes,parameters);
    }
    
    /**
     * Construct an object of the given named class with the provided 
     * constructor parameter types and values.  If there is no such class  
     * or no constructor is found that is appropriate to these parameters,
     * the method will return null;
     * 
     * @param className The fully qualified name of a Class object to be instantiated.
     * @param parameterTypes The types that form the desired constructor's method signature
     * @param parameters Optional parameters for the discovered constructor
     * @return an instance of the named class, or null if no such class or constructor is found.
     */
    public static Object construct(String className, Class<?>[] parameterTypes,
            Object... parameters) {
    	try {
    		Class<?> clazz = Thread.currentThread().getContextClassLoader()
                    .loadClass(className);
    		return construct(clazz, parameterTypes,parameters);
    	} catch (ClassNotFoundException e) {
            logger.log(Level.FINE,e.getClass().getName()+" thrown attempting to construct a " + className + ".", e); 		
    		return null;
    	}
    }

    /**
     * Construct an object of the given class with the provided 
     * constructor parameter types and values.  If there is no such class  
     * or no constructor is found that is appropriate to these parameters,
     * the method will return null;
     * 
     * @param c A Class object to be instantiated.
     * @param parameterTypes The types that form the desired constructor's method signature
     * @param parameters Optional parameters for the discovered constructor
     * @return an instance of the named class, or null if no such class or constructor is found.
     */
    @SuppressWarnings("unchecked")
    public static <T> T construct(Class<T> c, Class<?>[] parameterTypes,
            Object... parameters) {
    	try {
    		Constructor<T>[] constructors = c.getDeclaredConstructors();
            for (Constructor<T> constructor : constructors) {
    			if (ArrayUtils.equivalent(parameterTypes,constructor.getParameterTypes())) {
    				return (T)constructor.newInstance(parameters);
    			}
    		}
    		return null;
    	} catch (Exception e) { 
            logger.log(Level.FINE,e.getClass().getName()+" thrown attempting to construct a " + c.getName() + ".", e); 		
    		return null;
    	}
    }

}
